Various materials of printed wiring boards have been proposed so far. (e.g., patent references 1 to 6) Epoxy resin composition is required to exhibit heat-resistance for utilized as a printed wiring board, in view of recent trend in Pb-free soldering. Various epoxy resin composition have been developed to meet the requirement, such as dicyclopentadine-based epoxy resin, novolac-based epoxy resin, biphenyl-based phenol resin.    Reference 1: Japanese unexamined patent publication 2007-2053    Reference 2: Japanese unexamined patent publication 2005-336426    Reference 3: Japanese unexamined patent publication 2002-37865    Reference 4: Japanese unexamined patent publication 2002-226557    Reference 5: Japanese unexamined patent publication 2003-55537    Reference 6: Japanese unexamined patent publication 2006-124434